Hôm qua, Lan phải họp ở văn phòng đến rất trễ.

Yesterday, Lan had to be in a meeting at the office until very late.

Breakdown of Hôm qua, Lan phải họp ở văn phòng đến rất trễ.

• Lan: Lan
• rất: very
• ở: at
• hôm qua: yesterday
• phải: have to
• văn phòng: the office
• họp: to have a meeting
• đến: until
• trễ: late

Questions & Answers about Hôm qua, Lan phải họp ở văn phòng đến rất trễ.

What does phải mean in this sentence, and why is it used instead of something like đã?

In this sentence, phải is a modal verb meaning must / have to / be obliged to.

• Lan phải họp ≈ Lan had to attend a meeting / Lan had to be in a meeting.
• It expresses necessity or obligation, not past tense.

Vietnamese does not need đã here because the time phrase Hôm qua (yesterday) already shows it happened in the past. You could say:

• Hôm qua, Lan phải họp… (most natural)
• Hôm qua, Lan đã phải họp… (also correct, emphasizes that the obligation really did happen)

But đã and phải do different jobs:

• đã = past marker
• phải = must / have to

How is the past tense shown here if there is no verb ending like in English?

Vietnamese doesn’t use verb endings for tense. In this sentence, past time is indicated by the time expression, not by the verb:

• Hôm qua = yesterday → this alone makes the whole situation clearly past.
• The verb họp itself doesn’t change form.

So:

• Hôm qua, Lan phải họp… = Yesterday, Lan had to be in a meeting…
• If you removed Hôm qua, the sentence could be present, past, or future, depending on context:
  • Lan phải họp ở văn phòng đến rất trễ. → could mean Lan has to stay in a meeting at the office until very late (general / current obligation).

Why is there no pronoun like cô ấy (she) before Lan?

In Vietnamese, a person’s name itself commonly functions as the subject, similar to a pronoun. So:

• Lan phải họp… literally = Lan has to be in a meeting… but functionally it’s like She has to be in a meeting… (when everyone knows you’re talking about Lan).

If someone else is talking about her, they typically just use her name:

• Lan phải họp ở văn phòng đến rất trễ.

Using cô ấy is grammatically possible but much less natural here; Vietnamese strongly prefers actual names or kinship/pronoun words like chị, em, anh, cô, bác, nó, etc., depending on the relationship.

So the sentence is perfectly complete without an extra pronoun.

Could Lan herself say this sentence about her own actions, or would she change Lan to something else?

If Lan is talking about herself, she would normally not use her own name in this context. She would choose a self‑reference pronoun that fits the relationship with the listener, for example:

• To an older person or teacher:
  Hôm qua, em phải họp ở văn phòng đến rất trễ.
• In a formal context (e.g., to a boss, in writing):
  Hôm qua, tôi phải họp ở văn phòng đến rất trễ.
• To someone clearly younger:
  Hôm qua, chị phải họp ở văn phòng đến rất trễ.

Using your own name for yourself is mostly for talking to children, for “cute”/playful speech, or in some third-person style contexts (e.g. social media posts).

What exactly does họp mean? Is it a noun like “meeting” or a verb like “to meet”?

Họp is primarily a verb, meaning to have a meeting / to hold a meeting / to sit in a meeting.

• họp = to meet in a formal or semi-formal setting (work, class, organization, etc.)

Examples:

• Chiều nay chúng ta họp lúc ba giờ.
  This afternoon we meet / have a meeting at 3 p.m.
• Tôi đang họp.
  I’m in a meeting.

The noun “a meeting” is usually expressed as:

• cuộc họp = (a) meeting
  
  • Cuộc họp hôm qua kéo dài quá lâu.
    Yesterday’s meeting lasted too long.

In this sentence (Lan phải họp…), họp is clearly used as a verb: Lan had to be in a meeting / had to attend a meeting.

What is the difference between ở văn phòng and tại văn phòng? Could I use tại here?

Both ở văn phòng and tại văn phòng can mean at the office, but they differ in tone:

• ở văn phòng

  • Very common in everyday speech
  • Neutral, natural, conversational
  • Perfect for this sentence

• tại văn phòng

  • More formal, often seen in writing, announcements, reports
  • Still correct in speech, just a bit more “official”

So you can say:

• Hôm qua, Lan phải họp ở văn phòng đến rất trễ. (normal speech)
• Hôm qua, Lan phải họp tại văn phòng đến rất trễ. (slightly more formal tone)

Both are grammatically correct; ở is the best default in normal conversation.

What does đến mean in đến rất trễ? Is it like “to arrive” or like “until”?

Đến can mean to arrive or to / until, depending on context. Here it means until.

• đến rất trễ ≈ until very late

So the structure is:

• Lan phải họp ở văn phòng đến rất trễ.
  = Lan had to be in a meeting at the office until very late.

In this usage, đến introduces a time limit or endpoint:

• Làm việc đến 10 giờ tối.
  Work until 10 p.m.
• Chúng tôi nói chuyện đến khuya.
  We talked until late at night.

You could also hear tới used similarly:

• …họp ở văn phòng tới rất trễ.
  Same meaning, slightly more colloquial in some regions.

Could I drop đến and say Hôm qua, Lan phải họp ở văn phòng rất trễ?

You can say it, but the meaning changes and it sounds a bit odd.

• đến rất trễ = until very late → emphasizes the duration / end time.
• rất trễ directly after văn phòng can be interpreted more as describing how late the action is, but without clearly marking “until”.

Native speakers would normally:

• Keep đến (most natural):
  Hôm qua, Lan phải họp ở văn phòng đến rất trễ.
• Or specify the time more clearly:
  Hôm qua, Lan phải họp ở văn phòng đến khuya. (until late at night)
  Hôm qua, Lan phải họp ở văn phòng đến 10 giờ tối. (until 10 p.m.)

Without đến, …ở văn phòng rất trễ sounds like “at the office very late” but misses the smooth “until” idea. It’s not wrong grammar, just not the most natural phrasing for this meaning.

What is the role of rất in rất trễ? How would the meaning change without it?

Rất is an intensifier, similar to very.

• trễ = late
• rất trễ = very late

So:

• đến trễ = until late
• đến rất trễ = until very late (stronger emphasis)

If you remove rất:

• Hôm qua, Lan phải họp ở văn phòng đến trễ.
  = Yesterday, Lan had to be in a meeting at the office until late.

Still correct, just less strong. Rất is optional but adds emphasis to how late it was.

What is the difference between trễ and muộn? Could I say rất muộn instead of rất trễ?

Both trễ and muộn can mean late, and they are often interchangeable, but there are some preferences and nuances:

• trễ

  • Very common in Southern Vietnamese
  • Used in many everyday contexts:
    Anh ấy đến trễ. (He arrived late.)

• muộn

  • More common in Northern Vietnamese, and often perceived as slightly more formal/standard
  • Also widely understood everywhere:
    Anh ấy đến muộn.

In your sentence, both are acceptable:

• đến rất trễ (more Southern-feeling)
• đến rất muộn (more Northern/standard-feeling)

Meaning is practically the same: until very late. Choice depends mostly on region and personal style.

Why is Hôm qua at the beginning with a comma? Could it go somewhere else in the sentence?

Hôm qua is a time expression meaning yesterday. In Vietnamese, time expressions are very flexible in position, but certain positions are more natural.

Most natural options:

1. At the beginning, often with a comma (especially in writing):

   • Hôm qua, Lan phải họp ở văn phòng đến rất trễ.

2. After the subject:

   • Lan hôm qua phải họp ở văn phòng đến rất trễ.
     (Possible, but sounds a bit marked/emphatic; often used to contrast with another time.)

3. At the end (less common for this particular sentence, but possible):

   • Lan phải họp ở văn phòng đến rất trễ hôm qua.
     This can sound slightly awkward and is not the default way to say it.

Putting Hôm qua at the start is the clearest and most natural for a simple statement like this. The comma in writing just marks a pause; in everyday writing people sometimes omit it, and it’s still fine:

• Hôm qua Lan phải họp ở văn phòng đến rất trễ.

Is the comma after Hôm qua required?

No, it’s not strictly required. It mainly reflects natural speech rhythm.

• With comma (more formal/clear writing):
  Hôm qua, Lan phải họp ở văn phòng đến rất trễ.
• Without comma (very common in everyday text messages, informal writing):
  Hôm qua Lan phải họp ở văn phòng đến rất trễ.

Both are correct. The comma simply shows a small pause after the time phrase, which is how people normally say it aloud.

What is the overall literal structure of the sentence? How can I map it to English word by word?

Breakdown:

• Hôm qua = yesterday
• Lan = Lan (name, subject)
• phải = must / had to
• họp = be in a meeting / have a meeting
• ở = at / in
• văn phòng = office
• đến = until
• rất = very
• trễ = late

A fairly literal mapping:

• Hôm qua, = Yesterday,
• Lan = Lan
• phải = had to
• họp = be in a meeting
• ở văn phòng = at (the) office
• đến rất trễ. = until very late.

So the whole sentence:
Hôm qua, Lan phải họp ở văn phòng đến rất trễ.
≈ Yesterday, Lan had to be in a meeting at the office until very late.